Fluid heating apparatus



Dec. 20, 1938. R. A. FORESMAN Q I FLUID HEATING APPARATUS- Fi1 ed Aug. 31, 1936 5 Sheets-Sheet 1 INVENTOR Enema-r AJQmmsM ATTOR Y Dec; 20, R A. FQRESMAN FLUID HEATI'NG APPARATUS v Filed Aug. 51, 1936 3 Sheets-Sheet 2 I INVENTOR Boats-r A Foggsmw ATTORNXV I Dec. 20, 19 38.

' I R. A. FORESMAN FLUID HEAT ING APPARATUS Filed Aug. 51, 1956 5 Sheets-Sheet s I E lNvlggToR OBERT A. QEESMAN F\ G. 5

- ATTOR EY latented Dec. 20,

* PATENT. OFF-ICE FLUID HEATING APPARATUS Robert A. Foresman, Prospect Park, Pa.,' assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh; Pa;, a corporation of Pennsylvania Application August 31, 1936,..Sei'ial No. 98,755

14 Claims. (Cl; 122-30)".

invention relates to fluidheaters for use with a fuel burning structure of the rotatable annular grate type and has for an object to pro-V 7' vide an improved heater of this kind. W A further object of the invention is to provide an improved heater of the'character'set forth 7 having a relatively large amount of heat transfer 1 surface and which will occupy a relatively small amount of floorspace. Q

1 These and other objects areeffected by my invention as will be apparent from the following description and claims taken in connection with the; accompanying drawings. forming a part of :thisgapplication, iii-which;

.Fig. 1 is a front elevation of a fluid heater constructedin accordance with my invention;

Figs. 2, 3, and 4 are sectional views taken along the lines II--II, III-III and IV--IV of Fig. 1, respectively; and t 2 Fig. 5 isa developed sectional view of the heater looking outwardly from a line V-V which I have indicated on Fig. 4. 7

Referring to the drawings, I have shown my I improved apparatus including a plurality of A superimposed sections IO, N, and I2 which I will a refer to as lower, intermediate, andtop sections, respectively. The lower section It rests upon a -base member I3 which rotatably carries a circular grate structure shown at l4. A magazine struc- 3 ture l5 for fuel is, carried on a side of the struc-:

' ture and may be supported by the lower and intermediate sections l0, and l l as shown in Fig.

1. The foregoing defines the major elements of the heater structure and a description of each in detail will now be given.

-, *Refei'ence will now be had particularly to Figs. 1, ,4, and 5 which disclose best the construction of the lowersection III. The lower. section IU of the fluid heater includes an outer cylindrical wall I6, preferably providedwitha water space I1. and having first and second openings l8 and l9 formed therein, the firstof which isa passage for 1 ash and the second of which defines a flue for the discharge of products of combustion. Aninner I 'sp'ective water spaces 26, and ,21 communicating with the spaces and22. The'radial'wall 24 ex.--

tendsfrom the top of thesection downwardly and terminates inspaced relation with thebottom of the section Illv and with the grate l4 whereby an orifice or passage 28 is defined for the passage of fuel carried bythe grate (Fig. The radial wall 25 extends downwardly from the top of the section In and terminates adjacent the grate |4, saidwall 25 having an offset portion 29 formedctherein so that the bottom portion of the wall 25 which I have indicated at 3| in Fig. 5 is offset circumferentially with respect to the top of the wall 25. The water space 2''! may extend through the offset portion 29 and bottom portion 3| of the wall 25 as shown in Figs. 4 and 5. .5 The radial walls 24 and 25 define arcuate chambers 32 and 33 above thegrate; the first ofwhich is a combustion chamber and the second of'which defines a fuel receiving chamber or a lower extension of the magazine 5 for fuel. An arch structure 34 (Fig. 5) preferably provided with a water space 35, is disposed above the combustion chamber 32' and connects with the radial wall 25. The arch 34 extends horizontally from the radial wall 25 toward the radialwall 24, but terminates in spaced relation-therewith so that a substantially vertical gas passage 36 is defined adjacent to the wall 24. An upturned portion 31 of the arch 34 defines aside of the passage 36 and may include a portion of the water space 35 (Figs. 4 and 5). All of the various water spaces which hav'e been recited are,preferably, communicating.

The arch 34 defines an arcuate space 39 for gas above a portion of the combustion chamber 32, as shown best in Fig. 5. The openings l9 and |8 communicate, respectively, with the gas space 39 and the combustion chamber32. The lower sectangentially with respect to the grate l4 and may besecur'ed in the section l0 in any suitable manner, Further reference to the function of the ash deflecting plate 4| will be made hereinafter.

The construction of the intermediate section of the heating structure may be best understood by reference to'Figs. 1,3, and 5 andlincludes an outer shell '42, arcuate in'shape, and alined with the outer wall It of the lower section I0. Extending inwardly from the ends of the arcuate shell 42 are radiallyextending walls 43 and 44, connected at their inner ends at 45 and alined respectively with lower section l0. vThe lower ends of the arcuate shell" and thewalls 43and 44 are connected to 'the'radially extending walls 24 and 25 of the v a bottom plate 41 and the upper end of the arcuate shell 42 is connected to an upper plate 46 whereby a relatively large water chamber 48 is formed above the gas space 39 of the lower section.

The upper ends of the radially extending walls 43 and 44 are connected to a plate member 49 (Figs. 1 and 5) spaced below the top plate 46 whereby a horizontally extending water space 56 is defined which connects at both ends with the main water chamber 48. r

A plurality of fire tubes 5| are suitably secured in the end plates 46 and 41 and traverse the water space 48, the tubes 5| communicating at their,

lower ends with the gas space 39. For the sake of clearness, I have omitted showing the tubes in Fi 1.

The vertical and radially extending walls or plates 43 and 44 and the plate 49 define an armate magazine portion 52 that constitutes an extension of the fuel receiving chamber or magazine portion 33 in the lower section III. The outer shell 42 is cut away between the walls 43 and 44 so that the upper magazine portion 52 communicates with the magazine structure I5 disposed on the outside of the heater structure. In order to facilitate the gravitation of fuel to the magazine portions 52 and 33, the bottom walls of the outer magazine structure I5 may be inclined as shown An upper extension of the vertical gas passage 36 is shown at 54 and is formed by vertical radially extending walls or plates 55 and 56 joined at their outer and inner ends, respectively, by curved plates 51 and 58. All of the plates 55 to 58, inclusive, are joined to the upper and lower plates 46 and 41 of the section I I. It will be understood that the vertical extension 54 of the gas passage 36 may be defined by a plurality of tubes similar to those shown at 5| but I prefer to employ the relatively large passage 54 which is subjected to the water space 48 on all sides thereof.

The upper and lower plates 46 and 41 are provided with respective openings 6| and 62 (Fig. 1), the latter of which communicates, with the opening 23 formed in the lower section II]. Communication is thereby effected between the water spaces 48 and 22 of the sections II and I6, respectively. A suitable connection 63 for the passage of water between sections may be arranged on the outside of the structure and affords communication between the water chamber 48 and the outer water space H of the intermediate and lower sections II and I0, respectively.

As shown in Figs. 1, 2, and 5, the upper section I2 of the heater structure includes an annular water wall 65 having a space 66 formed therein and alined above the perimeter of the water space 48 and its horizontal extension 50. An inner column or drum 6! having a water space 68 is coaxially disposed within the wall 65 and'is provided in its bottom, with a water opening 69 registering with the opening 6| of the section II. Communicating between the water spaces 48 and 6 8, is, therefore, provided. a 7

A top wall II is provided for the section I 2 and connects the outer wall 65 and the column '61, which wall II includes a water space I2 communicating with the water spaces 66 and 68. The outer wall 65 and the column 61 define an annular gas space 13, beneath the top wall II, which communicates with the upper ends of the vertical gas passage 54 and the tubes 5| of section III. A radially extending balile I4 connects the outer wall '65 and column 61 and may include a water space I5, which baffle 14 is alined above the ver--- tical wall 56 of the section II.

The purpose of the wall or baffie I4 is to prevent gases, rising in the passage 54, from entering the tubes 5| immediately adjacent to the passage 54 and to effect a counter clockwise sweep of the gas, as viewed in Fig. 2 through the annular space 13 prior to its descent to the gas space 39 and flue I9 through the tubes 5|. The arrangement of tubes 5| and gas spaces I3 and 39 may be such that a single pass is effected by the gas as it traverses the section II but, preferably, the gas is directed through the section II in a plurality of passes. Accordingly, bafiies I6 and 'I'! are provided in the gas spaces I3 and 39, respectively, whereby a three-pass arrangement for the gases is provided through the tubes 5|, as shown by arrows in Fig. 5. Other arrangements of baffies may be employed for directing the gases through the section II in any desired number of passes. The baffles 16 and TI are preferably water containing, as shown.

Suitable connections for the passage of Water between the chamber 48 of section I I and the space 63 of the top section I2 may be provided on the exterior of the structure, as shown at I8. Water to be heated may be admitted to the outer wall space H of the lower section I0 by means of one or 'more conduits l9 and the heated water or steam is discharged from the wall space I2 of the top section I2 through a conduit 8|.

Suitable cleaningor inspection openings may be provided as shown at 82, in the top section I2 and at 83 in the bottom section III, each of which openings may be closed by suitable closure members as shown. Access to the fuel magazine I5 is provided by means of one or more doors 84.

The fuel burning apparatus for my improved heater is best shown in Figs. 1 and 5 and includes the annular grate I4 that is rotatably carried by the base I3. A pawl and ratchet mechanism 85 may be provided for rotating the grate I4, which mechanism 85 includes ratchet teeth 86 formed on a surface of the grate I4 and engageable by a pawl 87. The latter is pivotally supported by an arm 88, carried by a shaft 89that is oscillated in any suitable manner. As the latter is oscillated, the pawl 81 successively engages the ratchet 86 and effects step by step rotation of the grate I4 in a well understood manner.

A windbox 9| is formed within the base I3 and is substantially coextensive with the combustion chamber 32 disposed thereabove. Air is-admitted to the windbox 9| through an opening 92 in any well known manner.

Operation As the pawl and ratchet mechanism 85 is operated, step by step rotation of the grate is effected in clockwise direction, as viewed in, Figs. 2 to 4, inclusive, and in the direction of the dot and dash arrow in Fig. 5. Coal from the chamber or lower magazine portion 33, fed gravitationally to the grate, is carried by the grate through the opening 28 and is levelled to a predetermined depth by the bottom of the radial .wall 24. Ignition of the fuel is effected in or adjacent to the fuel discharge opening 28 and itpasses through successive combustion stagesas it is advanced through the combustion chamber 32.

Combustion of the fuel is substantially complete adjacent the radial wall 25 and the ash is deflected from the gratewby the scraper 4| in this region. -As the grate I4 passes beneath the scraper plate 4|, theash is .engagedthereby and g5 r isenovedrradially of the grate towardandi through I space "13 inthe top section l2. The gases then traverseithe gas space 13, the tubes and the gasspac'e 39 of the lower heater sectionv ID, as clearlyrshown by the arrows in Figs. 2 and 5 prior to their discharge through the flue opening I9.

In'theembodiment disclosed, thegases complete 'three 'ipasses through the tubes 5|, although any number of passes may be effected by suitable bai'tlinglas is understood.

, Water to be heated or vaporized enters the heater'atTJEI and is discharged at 8l.- Circulation of water through the spaces of the sections M, l l,-and |2.-is provided by the communicating openings 23 and 62 of the lower and intermediate sections, the openings BI and 69 of the intermediate-and top sections and by the exterior connecting conduits 63 and 18, it being understood that the various portions of the water spaces in individual sections are communicating.

; I From the foregoing, it will be apparent that I- have provided an improved fluid heater for a fuel burning structure of the rotatable annular grate typegwherein the amount of heat transfer surface per unit of floor area occupied is relatively high. This feature is obtained by combining an improved tubular type boiler section having ,a'large amount of heat transfer surface with otherfsections adapted for use with a rotatable grate and defining therewith, a chamber for the combustion of fuel. By disposing a gas space adjacent the bottom of the heater structure and directing gases from the combustion chamber to.

the gas space in a plurality of passes through the tubular boiler section, a relatively long path for the hot gases is provided, prior to their discharge from the heater.

Furthermore, a relatively large amount of fuel may be stored in the magazine, a substantial portion ofwhich is defined by the sections of my improved boiler structure. Accordingly, the capacity or size of the magazine structure that is assembled onthe exterior of the heater may be reduced, with a reduction in the space necessary forjinstallation of the heater. The magazine and the opening for removal of ash are disposed on a single side of the structure, so that servicing "of the heater may be effected on a single side thereof.

The number or size of'the intermediate tubular type boiler sections maybe varied for obtaining. the desired amount of heat transfer surface and assembled to top and bottom sections of standard size and design. The size of the various elements or sections forming the heater structure may be kept within limits so that passage thereof through conventional wall openings is permitted. This is desirable, as I have found that the heater is especially applicable for apartment or other relatively large heating applications wherein installation in basements is necessary; I In: the caseofexisting buildings, it is desirable, and occasionally necessary, that the heaterbe admitted to the basement through a relatively small door opening. I

WhileI have shown my invention in but one form, it :will be obvious to those skilled in the art' lthatit is not so limited, but is susceptible of various :changes and'modifications without departing from the spirit thereof,'and I desire, therefore, thatonly such limitations shall be placed :thereupon as are imposed by the prior art or as are specifically set forth in the appended claims. 7

' What I claim is:

1. In fluid heating apparatus, the combination of a rotatable annular grate, an outer wall disposed above the perimeter of the grate, an inner wall arranged above an inner portion of the grate, said inner and outer walls defining an annular space above the grate, means for dividing said space into a combustion chamber and a fuel receiving chamber above respective arcuate portions of the grate, an arch arranged in the combustion chamber and defining a gas space thereabove, a structure disposed above the combustion chamber and having a space therein for fluid to be'heated, a plurality of tubes extending through said fluid space for conveying products of combustion from the combustion chamber to said gas space and means for removing products of combustion subsequent to their passagethrou h the tubes and gas space.

2. In fluidheating apparatus, the'combination of a rotatable annular grate, an outer 'wall disposedabove the perimeter of the grate and having a space therein for fluid to be heated, a vertical 'drum' disposed above an inner portion of the grate and enclosing a space for fluid to be heated, said outer wall and drum defining an annular space above the grate, means for dividing said space into a combustion chamber and a fuel receiving chamber'above respective arcuate portions of the grate, an arch arranged in the combustion chamber and defining a gas space thereabove, a structure superimposed upon said outer wall. and said drum and having a fluid space therein communicating with the fluid spaces of the drum and outer wall, a plurality of tubes extending through the fluid space of said superimposed structure and providing communication between the combustion chamber and said gas space, and means for removing gases of combus tion subsequent to their passage through the tubes and the gas space.

3. Influid heating apparatus, the combination of a rotatable annular grate, inner and outer walls disposed above inner and outer portions of the grate and defining an annular space thereabove, first and second circumferentially spaced walls connecting said inner and outer walls and dividing said space into a pair of arcuate chambers, the first of which is a combustion chamber and thesecond of which defines a lower portion of a fuel magazine, an arch structure disposed above a portion of the combustion chamber and defining a gas space thereabove, a heating structure disposed above said inner and outer walls and having a space formed therein for fluid to be heated, means defining an upper portion of the fuel magazine within said heating structure, means including a plurality of tubes extending through the fluid space of the heating structure for conveying gases of combustion from the combustion chamber to said gas space, and means for discharging the combustion gases subsequent to their passage through the tubes and the gas space.

4. 'In fluid heating apparatus, the combination of a' rotatable annular grate, an outer wall disposed. above the perimeter of the grate, an inner wall arranged above an inner portion of the grate, said inner and outer wall defining an annularspace above the grate, means for dividing said space into a combustion chamber and a fuel receiving chamber above respective arcuate portions of the grate, an arch arranged in the com-' bustion chamber and defining a gas space thereabove, an intermediate structure disposed above said inner and outer Walls and having a space therein for fluid to be heated, said intermediate structure including a substantially vertical passage for conveying gases from the combustion chamber, a top structure carried by the intermediate structure and having separated gas and fluid spaces therein which communicate, respectively, with the gas passage and the fluid space of the intermediate structure, a plurality of tubes traversing the fluid space of the intermediate structure for conveying gases of combustion from the gas space of the top structure to the gas space above the arch, and means for removing gases from the last-mentioned gas space.

5. The combination as claimed in claim 4 having means for directing the gases of combustion through the tubes in a plurality of passes.

6. In water heating apparatus, the combination of a rotatable annular grate, an outer water wall disposed above the perimeter of the grate, a vertical water drum arranged above an inner portion of the grate, first and second circumferentially spaced 'water walls connecting the drum and said outer wall and defining a fuel rec'eiving space and a combustion chamber above respective arcuate portions of the grate, saidfirst circumferentially spaced wall having its bottom portion spaced above the grate for defining an opening through which fuel passes to the combustion chamber as the grate is rotated, said second circumferentially spaced wall terminating adjacent the grate, means disposed adjacent the second circumferentially spaced Wall for deflecting ash from the grate, said outer water Wall having an opening therein for the passage of the deflecting ash, an arch structure having a water space therein and arranged above the combustion chamber, said arch defining a gas space above a portion of the combustion chamber, an intermediate element disposed above said outer wall and having a, fluid space therein, means defining 'a vertical gas passage in said element which communicates with the combustion chamber, said element having a fuel magazine formed therein disposed above said fuel receiving space, a top structure having-separated gas and fluid spaces therein, the former of which communicates with said vertical gas passage, a plurality of tubes traversing'the fluid space of said intermediate element and providing communication between the gas space of the top structure and said gas space above the arch, and means for removing gases of combustion from the gas space above the arch.

'7. In fluid heating apparatus, the combination of a rotatable annular grate, inner and outer walls disposed above inner and outer portions of the grate and defining a combustion chamber above the grate, means for depositing fuel upon a portion of the grate for combustion in the combustion chamber, means for removing ash from a second portion of the grate, an arch disposed in the combustion chamber and defining a gas space thereabove, a fluid heating element 'disposed above the inner and outer walls and having a'space for fluid to be heated, a plurality of tubes extending through said fluid space and providing communication between the combustion chamber and the gas space, and means for removing gases of combustionsubsequent' to their passage through the tubes and said gas space.

8. In fluid heating apparatus, the combination of a rotatable annular grate, inner and outer walls disposed above inner and. outer portions'of the grate and defining a combustion chamber above the grate, means'for depositing fuel upon a portion of the grate for combustion in the combustion chamber, means for removing ash from a second portion of the grate, an arch disposed in the combustion chamber and defining a gas space thereabove, a heater element disposed above the combustion chamber and said gas space and having a space formed therein for fluid to be heated, said element including a gas passage extending upwardly from the combustion chamber, a top member having separated gas and fluid spaces, the former of which communicates with said gas passage, a plurality of tubes extending through the fluid space of the heater element and providing communication between thegas space of the top member and the gas space beneath the heater element, and means for removing gases of combustion subsequent to their passage through the tubes and said gas spaces.

9. In fluid heating apparatus, the combination of a rotatable annular grate, inner and outer walls disposed above inner and outer portions of the grate and defining .a combustionchamber above the grate, means for depositing fuel upon a portion of the grate for combustion in the combustion chamber, means for removing ash from a second portion of the grate, an arch disposed in the combustion chamber and defining a gas space thereabove, a fluid heating element superimposed above the'inner and outer walls and including separated fluid and gas passages therein, means for admitting fluid to be heated to said fluid passages, said gas passages providing communication between the combustion chamber and the gas space thereabove, and means for removing gases of combustion from the apparatus subsequent to their passage through said gas passages and the gas space.

10. In fluid heating apparatus, the combination of a rotatable annular grate, an outer wall disposed above the perimeter of the grate, first, second, third, and fourth vertical walls extending generally in a radial direction and disposed above the grate, said first and second walls being joined at their inner and outer ends and defining a fuel magazine for the fravitational feeding of fuel to the grate, said third and fourth walls being joined at their inner and outer ends and forming a passage for the upward circulation of gases of combustion from the grate, said magazine and passage being spaced apart for defining a chamber forfluid to be heated above a portion of the grate, outlet means for gasesof combustion EX-e tending through said fluid heating chamber and means for conveying the gases 'of combustion from the upper portion of said passage to said outlet means. p g

11. In fluid heating apparatus, the combination of a rotatable annular grate, an outer wall disposed above the perimeter of the grate, first, second,,third, and fourth vertical walls extending generally in a radial direction and disposed above the grate, said first and second walls being joined at their inner and outer ends anddeflning afuel magazine for the gravitational feeding of fuel to the grate, said third and fourth walls being joined at their inner and outer endsand forming apassage for the upward circulation of gases of combustion from the grate, said magazine and passages being spaced apart for defining a chamber ,for fluid to be heated above a portion of the grate, means provided in said fluid heating chamber for conveying gases of combustion downwardly in heat transfer relation therewith, means providing communication between an upper portion of said passage and said gas conveying means and an outlet for the gases of combustion communicating with the bottom portion of the gas conveying means.

' 12'. :In fluid heating apparatus, the combination of a rotatable annular grate, a structure disposed above'a segment of the grate and defining wall members extending generally in a radial direction and having their respective inner and V outerend'portions joined for defining a fuel magazine above a second segment of the grate for the. gravitational feeding of fuel thereto, said magazine including a topwall having a space therein for fluid to be heated, means defining a passage for combustion gases within said fluid heating chamber, means spaced from said gas passage for directing the gases downwardly through said fluid heatingchamber, means for conveying, gases from the upper portion of said passage in heat exchanging relation with the top wallof the magazine and thence to said gas directing means, and means for discharging the gases from the apparatus subsequent to their pas "sage through the gas directing means.

to be heated above said combustion chamber, first and second walls extending generally in a radial direction and having their respective inner and outer end portions joined for defining a fuel magazine above a second portion of the grate, first and second means for conveying gases of combustion through said fluid heating chamber, said last-mentioned means being spaced circumferentially one from the other, means defining a passage above the fuel magazine for providing communication between the ends of said gas conveying means, and fluid containing means disposed between the magazine and said passage.

' 14. In fluid heating apparatus, the combination of arotatable grate structure, means defining a chamber above the grate structure, a fiuid heating element disposed above the grate structure and having a space therein for fluid to be heated, means for depositing fuel upon a segment of the grate within a first zone of said chamber, means disposed above a second zone of the chamber for defining a passage for gases of combustion within the fluid heating element, a plurality of tubes disposed above a third zone of the chamber for conveying said gases in heat exchanging relation with the fluid in said space, a fluid cooled wall structure disposed between said tubes and the portion of the grate in the third zone of the'chamber, means for directing the gases successively through the gas passage and said tubes, means for discharging the gases subsequent to their passage through the tubes, and means for advancing the grate through said zones of the chamber.

ROBERT A. FORESMAN. 

